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DHCP Reservations
It is a Windows 2012 Server running DHCP passing out IPs in the range 192.168.1.100-254
I am having trouble making a reservation at 192.168.1.4. Is that because it doesn't fall in the range of 100-254?
Kind of a awkward question....
I am having trouble making a reservation at 192.168.1.4. Is that because it doesn't fall in the range of 100-254?
Kind of a awkward question....
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A DHCP reservation is what it says and the reservation must fall within the DHCP scope. Change the IP to within the scope or use a Static IP address.
A DHCP reservation outside of the DHCP range does not make sense. A reservation is intended to pin a DHCP IP address to a MAC address, after it has been allocated. Any address outside of the DHCP scope needs to be a static one.
Odd, I have been creating DHCP reservations outside of the main pool for decades now. Works with NT 3.51, NT 4.00 Windows 2000, 2003, and 2008. I have never tried on a 2012 server, but I would be surprised if it differed.
This makes perfect sense; on the site where I am now sitting, workstations have IPs in a range from 192.168.10.100 - 192.168.10.199, a single pool doles them out. Printers are from 192.168.10-50 - 192.168.10.70, via reservations. All printers are runnig with reservations outside of the pool, but in the same subnet, as is required in the question.
This makes perfect sense; on the site where I am now sitting, workstations have IPs in a range from 192.168.10.100 - 192.168.10.199, a single pool doles them out. Printers are from 192.168.10-50 - 192.168.10.70, via reservations. All printers are runnig with reservations outside of the pool, but in the same subnet, as is required in the question.
Hmm, the plot thickens!
Here is an article claiming that this behaviour changed with Server 2008R2.
https://support.microsoft.com/en-us/help/2005980/you-cannot-add-a-dhcp-reservation-which-is-outside-of-the-scope-distribution-range-in-windows-server-2008-r2
I, however have a 2008R2 here server where this works just fine.
Here is an article claiming that this behaviour changed with Server 2008R2.
https://support.microsoft.com/en-us/help/2005980/you-cannot-add-a-dhcp-reservation-which-is-outside-of-the-scope-distribution-range-in-windows-server-2008-r2
I, however have a 2008R2 here server where this works just fine.
Yes, you can add reservations outside of the DHCP scope. I've done that on 2008r2 too for exercising.
As said, doing that is nonsense. If you want to keep a record of used IP addresses, do so by using static DNS entries in case the devices don't register themselves (otherwise DNS is already up-to-date).
Using DHCP reservations require to enter the MAC address, and there is no link to a name - this combines useless info with the lack of useful info.
As said, doing that is nonsense. If you want to keep a record of used IP addresses, do so by using static DNS entries in case the devices don't register themselves (otherwise DNS is already up-to-date).
Using DHCP reservations require to enter the MAC address, and there is no link to a name - this combines useless info with the lack of useful info.
The device name shows up when a DHCP lease becomes active, just like any DHCP lease.
Here is a screenshot. This is a Windows10 PC, targeting a 2008R2 server.
Here is a screenshot. This is a Windows10 PC, targeting a 2008R2 server.
That is why it was an awkward question. In thinking about it logically it could go either way. The Reservation is done by the DHCP Server but that doesn't necessarily equate to it having to be in the scope range. The reason is stupid anyway. A screw up by HPE on their 19XX and 16XX series switches. They put all these neat NTP features in but but forgot to put a place in the GUI to set gateway address. Oops! The NTP works if you let it go DHCP but I like knowing where my switches are. Usually static IP them. Hence the shot at a reservation. HPE has been living off their name for way too long. Even if you look at the MAC Address (Unique ID) that the DHCP Server picks up it is always like 23412412953987238579893257
If your IP address is outside the DHCP scope, why not just use a Static IP address. Yes, you need a small document to list the IP addresses you use, but it would solve your problem very well.
I love using static IP addresses. That is the way it should be but as mentioned above when I use a static IP address there is no place to put a gateway address and as a result none of the NTP functions work because without a gateway address the switch has no internet. I don't know what HPE was thinking. Obviously they weren't.....
Yes. A total bonehead move. I opened a case with HPE a year ago and there response was "we are trying to make a low cost switch and had to omit that feature" yet they put stuff in for Daylight Savings, NTP and the rest. There are ways to do it:
On both the 1920 and 1620 you can use the console cable and set the gateway via the CLI but how inconvenient is that? Serial ports went out with mini skirts back in the 70s.
On the 1920 you can telnet to it and set it with the CLI or use a static route.
They had room to put in this real annoying captcha verification when you log in to the switch but didn't have the room to set a gateway address? Kind of like Symantec. They have been living off their name way too long. Maybe it is time to change things up.
On both the 1920 and 1620 you can use the console cable and set the gateway via the CLI but how inconvenient is that? Serial ports went out with mini skirts back in the 70s.
On the 1920 you can telnet to it and set it with the CLI or use a static route.
They had room to put in this real annoying captcha verification when you log in to the switch but didn't have the room to set a gateway address? Kind of like Symantec. They have been living off their name way too long. Maybe it is time to change things up.
You should be able to change the DHCP range to the full network, then exclude the range up to 99, and then do a reservation.
For the record the Reservation outside the scope did work. I must have pulled an HPE when I tried it the first time. Something that document says shouldn't work in 2012 R2 but does. The actual MAC address is 356338612e333836342e346438
Rather then jumping through all these hoops it sure seems like the simple approach would be for them to add a place to set a gateway address in the GUI but what do I know? Thanks guys....
Rather then jumping through all these hoops it sure seems like the simple approach would be for them to add a place to set a gateway address in the GUI but what do I know? Thanks guys....
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